John Cuthber

OK, so you didn't say it was natural; you just said it wasn't like the artificial ones. I still wonder why you make the distinction.

Rather ironically, because I'm not in the US, I can't watch that video.

Only if it was a very small bit of metal, or one that was very easy to melt. Having said that, because the metal is in a vacuum there's no way for it to lose heat by convection or conduction (throughh the vacuum) so it may take less heat to melt than you would normally expect.

Glasss is pretty much indifferent to nitric and sulphuric acids. Whether ot not you would survive playing with them is another matter.

"I'd be interested in watching you guys figure out a point system for a single list, myself." Two years ago we might have bothered.

1 Marie Curie was not a government. 2 Marie Curie extracted polonium. Therefore you don't need a government to get polonium. Why did anyone ever think you did? Also, re. "If you have Beryllium nearby, the alpha collides with it and pops a neutron out." Actually, something like 999940 times in a million, it doesn't. I'm not sure about the figures but the yield is certainly poor.

There's certainly tubing on ebay. I have no connection with this seller, nor have I bought anything from them but I have noticed that they have been around for a while. http://business.shop.ebay.co.uk/Medical-Lab-Equipment-/11815/i.html?_catref=1&_fln=1&_ipg=&_ssn=tubingbypost&_trksid=p3911.c0.m282

Presumably you never walk diagonally across a town square because the length of the diagonal isn't rational. For those who hadn't spotted it I was refering to this joke. http://www.google.co.uk/imgres?imgurl=http://rlv.zcache.com/get_real_be_rational_card-p137700676799757647qi0i_400.jpg&imgrefurl=http://www.zazzle.com/get_real_be_rational_card-137700676799757647&h=400&w=400&sz=17&tbnid=OIoplMqMyBQShM:&tbnh=124&tbnw=124&prev=/images%3Fq%3D%2522get%2Breal%2522%2B%2522be%2Brational%2522&usg=__1olZB2MTEM10YWelm4NCMAhMI9s=&ei=uEkhS_WEOIuL4QbA4JHfCQ&sa=X&oi=image_result&resnum=1&ct=image&ved=0CAcQ9QEwAA

" has none of the chemicals that artificial sweeteners rely on." No, it has other chemicals instead. But since they are natural we know that they are all perfectly healthy. Seriously, why even mention the "artificial vs natural" bit? If there are adverse effects then that's independent of the origins of the material.

Get real.

"My question is this, is there any quick test I can use to detect the presence of pharmaceuticals in tap water." Probably not, or at least not at the sort of levels I would expect. Sertraline is probably as good an example as any. There were, according to WIKI about 30 million prescriptions for it in the US in 2007. Typical doses are 100 mg a day so that's about about 3 tons a day. Per capita water use in the states is about given as about 70 gallons a day. About 265 litres a day. There are about 300 million people in the US so that's about 78 million tons of water a day for domestic use. So, on average you are down to about 40 parts per billion. Then you need to add industrial use of water and storm drainage. Then there's the fact that some (perhaps most) of it will be destroyed metabolically, rather than excreted as such. My guess is that you are talking about parts per trillion in many cases, and that's for the most heavily prescribed antidepressant. There's some data here http://www.speclab.com/compound/c58082.htm about caffeine in river water- the levels are low ppb. A lot more people use caffeine than antidepressants. Then there's the fact that municipal water supplies are cleaned up before use. I doubt that I (as a professional chemist with experience in pharmaceutical measurements and access to a well stocked lab) could measure the amounts of antidepressants in most drinking water unless something had gone catastrophically wrong. Sorry.

Frankly, I think they are mocking flat earthers. The two papers are pitching slightly different versions but both are saying that we need to stop listening to the people trying to derail the important issues, get off our butts and do something.

There's a classic "spot test" using urease and detecting the ammonia produced by the pH change. This sort of thing might work too. http://www.ncbi.nlm.nih.gov/pubmed/4779897

You seem to have got the bit abnout the azeotropes and the British art of understatement. The yellow colour is probably due to some trash in the acid. Iron compouinds in HCl give yellow colours and so do sugars (that means paper ad cotton dust from a towel as well as the stuff you put in the tea). For the simple version of adding acid to salt and heating it you know the reactions over when the stuff stops giving off gas. Sometimes you can see this and sometimes it's basicly a judgement call. In this case, when there's no more gas being given off, the stuff will try to suck back into the gas generator (and you really don't want that.) It's not entirely a joke when that say chemsitry is as much an art as a science.

OK, so just over 1 paper per country isn't a good hit rate. Here's what another (fairly well respected) newspaper had to say on the subject. The might not have shared the editorial but they seem to have the same sentiment. from http://www.timesonline.co.uk/tol/comment/cartoon/

If I stand on the branch of a tree near the runk and walk outwards the branch will break. Not many people would describe that as the timber "flowing". Similarly, over long periods of time the movement of bits of the earth's crust caused by gravity and the upwelling of magma produce huge forces that break rocks. The broken rocks can get shoved aside then cold-welded back together. This isn't the behaviour of a liquid- it's the behaviour of a solid under sufficient stress that it breaks. Rocks are not liquid on any timescale but they will deform if subject to sufficiently great forces.

HM customs will assume that any still is used for alcohol and ask why it's not licensed. They don't care about science. Most labs should have a license but don't bother. Anyway, what do you know about azeotropes? http://en.wikipedia.org/wiki/Azeotrope if you have a mixture of water an HCl that's about 20.2% HCl by weight and distill it it will come over as 20.2% but if you start with a lower concentration then water distills over first then you get the azeotropic mix (about 20%). Similarly, if you start with more than 20.2% then HCl gas will come over first (and fill up your room) until the concentration in the pot falls to 20.2% then that mixture will distill. It's a bit more complicated if there's other stuff present but I'm fairly sure that if you make a mixture of H2SO4, NaCl and H2O that's equivalent to a little under 20% HCl and distill it you will get nice clean 20% HCl Do you know how to calculate the proportions needed?

Hi What aparatus do you have? If you have a still (or the bits to make one) then (1) you are probably in breach of the law in many countries but (2) you are well placed to make HCl. You can distil a solution of HCl from a mixture of NaCl, H2SO4 and water (be careful mixing them). Also, if you plan on doing much chemistry you should think about getting a balance- it makes things so much easier. For reasons that I don't understand there are lots of blances on ebay marketed for people who want to measure "herbs". I'm not that fussy when I put a sprig of parsley on the fish before I serve it but I guess some people want to add exactly the right amount of mint to their sauce. Whatever their reasons, there must be lots of them because they have established a market. I don't mind because it means that I can buy a half-decent balance for not a vast amount of money. I bought mine in an electronics shop and paid cash so if anyone is setting up a database of "People who worry to much about the weight of 'herbs' " I'm not on it. I understand that it's difficult for you to get out to buy stuff but a lot of things are up for sale on eBay so you might want to look there.

Thanks for that site. It tells me that because of Skitt's law this post, which tells you that you put too many capital letters in "You're missing a Definite Article, an Apostrophe, and a Period. ", will contain at least one grammatical error.

It's not what I'd call trivial. http://en.wikipedia.org/wiki/Hagen%E2%80%93Poiseuille_equation

I think this is the only one that will make much odds to me. http://www.london2012.com/

Filter the solution while it's hot (obviously, this might be tricky). That way you remove dust and such that can act as a nucleation point.

Rinsing hair with acid would not only be stupid from the obvious point of view, but it wouldn't work. Adding acid to soap or the scum formed from soap and hard water peoduces a greasy mess of fatty acids.

IIRC ptfe melts at about 325C and you fry things at about 250C.

Over the last few months it has stopped being late Summer/ early Autumn and is now Late Autumn/ Early Winter. On the whole this has been accompanied by a fall in temperatures. I predict that this trend will reverse in a few months' time. I also predict that night time tendst to be less well lit than daytime and that rain is generally wet.